diff --git a/ethcore/src/block_queue.rs b/ethcore/src/block_queue.rs
index 1fe31ba19..e14f2a06a 100644
--- a/ethcore/src/block_queue.rs
+++ b/ethcore/src/block_queue.rs
@@ -79,6 +79,8 @@ struct Verification {
 	bad: HashSet<H256>,
 }
 
+const MAX_UNVERIFIED_QUEUE_SIZE: usize = 50000;
+
 impl BlockQueue {
 	/// Creates a new queue instance.
 	pub fn new(engine: Arc<Box<Engine>>, message_channel: IoChannel<NetSyncMessage>) -> BlockQueue {
@@ -290,7 +292,7 @@ impl BlockQueue {
 	pub fn queue_info(&self) -> BlockQueueInfo {
 		let verification = self.verification.lock().unwrap();
 		BlockQueueInfo {
-			full: false,
+			full: verification.unverified.len() + verification.verifying.len() + verification.verified.len() >= MAX_UNVERIFIED_QUEUE_SIZE,
 			verified_queue_size: verification.verified.len(),
 			unverified_queue_size: verification.unverified.len(),
 			verifying_queue_size: verification.verifying.len(),
diff --git a/sync/src/chain.rs b/sync/src/chain.rs
index 9752a5013..8b0b52080 100644
--- a/sync/src/chain.rs
+++ b/sync/src/chain.rs
@@ -376,7 +376,7 @@ impl ChainSync {
 			trace!(target: "sync", "Ignored unexpected block bodies");
 			return Ok(());
 		}
-		if self.state  == SyncState::Waiting {
+		if self.state == SyncState::Waiting {
 			trace!(target: "sync", "Ignored block bodies while waiting");
 			return Ok(());
 		}
@@ -995,7 +995,11 @@ impl ChainSync {
 	}
 
 	/// Maintain other peers. Send out any new blocks and transactions
-	pub fn _maintain_sync(&mut self, _io: &mut SyncIo) {
+	pub fn maintain_sync(&mut self, io: &mut SyncIo) {
+		if !io.chain().queue_info().full && self.state == SyncState::Waiting {
+			self.state = SyncState::Idle;
+			self.continue_sync(io);
+		}
 	}
 }
 
diff --git a/sync/src/lib.rs b/sync/src/lib.rs
index 40b67dc5b..f3b43396c 100644
--- a/sync/src/lib.rs
+++ b/sync/src/lib.rs
@@ -107,6 +107,7 @@ impl NetworkProtocolHandler<SyncMessage> for EthSync {
 
 	fn timeout(&self, io: &NetworkContext<SyncMessage>, _timer: TimerToken) {
 		self.sync.write().unwrap().maintain_peers(&mut NetSyncIo::new(io, self.chain.deref()));
+		self.sync.write().unwrap().maintain_sync(&mut NetSyncIo::new(io, self.chain.deref()));
 	}
 }